[ramonesfreak]

when i had a banjo, i did not have many problems with it. i live in upstate NY where there are dramatic humidity and temp changes and extreme dryness in winter.

keep it in the case when not playing.

watch 1) the fret ends for sharpness which indicates the wood is drying out and shrinking and
2) mold/mildew growing in the case if very humid....maybe toss in some of those moisture absorbing packets.

otherwise, i wouldnt worry too much about excess humidity since the body is metal